Various grafts have been described in the literature that have attempted to offer solutions to the problem of reducing leakage of fluids from puncture sites following removal of the puncturing object. Typical graft materials for these grafts, which are most typically grafts intended for arteriovenous access wherein the graft may be pierced repeatedly, at intervals, by dialysis needles, are polyethylene terephthalate (PET) and expanded polytetrafluoroethylene (ePTFE). These grafts are typically tubular grafts, although planar sheet grafts, often for use in patching a portion of the surface of a tube, are also known.
A construction that has been described previously in various forms for reduced leakage involves the use of laminates of the above materials with a layer of a self-sealing material such as an implantable elastomeric material. These elastomeric materials are typically silicone, polyurethane or fluoroelastomers. The use of one layer of graft material joined to one layer of elastomeric material has been described, although the most frequently described laminates involve a layer of the elastomeric material that is covered on both surfaces (e.g., inner and outer surfaces) by a layer of the graft material. The layers of graft material may be the same or may be different materials on the two surfaces; the graft materials may also differ in thickness, bulk density, porosity, orientation or other attributes even if they are essentially of the same chemical makeup.
A particular variation of these laminates, particularly for tubular constructions, involves the use of a tubular elastomeric material component that has been everted (i.e., turned inside out) prior to laminating this tube to one or more layers of graft material). The everted tube of elastomeric material is under circumferential compression at its luminal surface while the abluminal surface is under circumferential tension.